There are fourteen bones in the face; the two that make up the jaw are the maxillae (upper jaw) and the mandible (lower jaw). The mandible, like the maxilla, contains sockets for the 32 teeth, which are embedded in fibrous tissue. Teeth are hard, bonelike structures in the upper and lower jaws of human beings and many kinds of animals. They are the hardest parts of the body. Muscles in the head are important to the processes of chewing and swallowing. They are responsible for facial expressions, such as smiling or frowning. A system of muscles and tendons connects the head to the spinal column, the collarbone and the shoulder blades. These muscles and tendons control the movement of the head.
The lower jaw is the only bony part of the face that moves. There are 32 permanent teeth, 16 in each jaw. Each jaw has 4 incisors, 2 canines, 4 premolars and 6 molars.